Over the past decade medical simulation has been experiencing explosive growth and widespread adoption. There are now over 1000 medical simulation centers in the US alone, in medical schools, nursing schools, hospitals, military simulation centers and schools of allied health professions (e.g., paramedics). Just as flight simulation has enabled risk-free training or pilots and resulted in substantial increases in safety, healthcare training is seeking similar benefits from simulation, including objective, criterion-based training, promotion of patient safety and increases in training efficiency. Simulation offers hands-on, experiential learning without exposing real patients to risk. It enables objective assessment (via sensor-based measurement of performance metrics), standardized practice and the ability to learn from mistakes without harm to a patient.
Although there are many varieties of medical simulators, from simple physical models to haptic-enabled virtual reality systems, the most common simulator is the full-body mannequin trainer. The two largest commercial firms producing such mannequin simulators have over 12,000 systems deployed worldwide. Mannequin simulators are designed to approximate the appearance and some of the clinical responses of a human patient, and offer the ability to display clinical signs such as palpable pulses, blood pressure, chest rise and fall with ventilation, and pupils that dilate in response to light. A fundamental limitation of current mannequins for training is that their internal structures (with limited exceptions such as airways) bear no resemblance to actual human anatomy. Like humans, they are mainly visually opaque. This attribute limits the ability for a student training with the mannequin to perform physical “dissection” on a mannequin or “peer behind the curtain” of the skin surface to explore the internal consequences of their external interventions.
For teaching many patient interactions or procedures (e.g., without limitation, endotracheal tube insertion, Foley catheter placement, bronchoscopy, central line placement) it would be advantageous if patients were “see through” so that a trainee could see what was actually occurring within the body as the trainee manipulated a tool or device. Presently, systems exist that project simulations of internal structures onto a body, however such systems do not allow for interaction by a trainee and do not provide feedback as to foreign structures, such as medical instruments, placed into a body. One such system projects computer generated images of anatomy onto a rigid white body form. The position and orientation of the form is tracked and the images are transformed appropriately so that it appears to users that they can rotate the body and see the internal anatomy from different orientations. Such a system, while offering potential utility for the study of anatomy, does not provide for procedural simulation, i.e., it does not track the position of medical devices and display their internal representations in accurate relationship to internal structures, does not display displacements or other positional alterations of internal structures as they are contacted by medical devices and does not allow interaction with medical devices to be viewed internally. Such system also requires that the images be viewed through a small hand-held window frame which is tracked in order to correct for parallax errors. The use of such viewer window does not lend itself to group learning environments as accurate viewing is limited to a single person at a time.
As such, there exists a need for improved systems and methods for medical teaching and training purposes including, without limitation, those procedures that involve the external manipulation of a medical device that is moving or acting inside the body. There may be significant advantages to a system that during training enables the visualization of the internal portions of tools and devices and the relevant anatomy with which the tools interact. Such real-time, interactive visualizations may permit trainees to develop better mental models of the internal consequences of their external actions. These mental models may in turn help trainees to acquire skills more quickly and efficiently, achieve higher levels of proficiency, and help them more effectively to identify and avoid potential errors that could cause harm in an actual patient.